Screen printing machine for cylindrical or conical bodies

ABSTRACT

A screen printing machine for monochrome and polychrome printing of cylindrical and conical bodies. The machine comprises a printing stencil secured to a reciprocating slide. A fixed doctor blade is also provided. The stroke of the reciprocating slide is infinitely adjustable. The bodies to be imprinted are rotated about their longitudinal axes in synchronism with the printing stencil. There is further provided an eccentric drive for linearly displacing the printing stencil.

Unite States Patent 11 1 1111 3,792,657

Kammann Feb. 19, 1974 [5 SCREEN PRINTING MACHINE FOR 3,368,481 2 1968Brockmann 101 40 CYLHNDRICAL 0 CONICAL BODIES 3,436,988 4/1969 Simonton74/600 X 3,521,298 7/1970 Morel et a1. 101/40 [76] Inventor: WilfriedKammann, 1 Bustedter Strasse, Suedlengern, Ueber OTHER PUBLICATIONSBuende, Germany Grodzinski, Paul; pp. 147 and 149 of Applying Eccen-[22] Filed: June 26 1969 me Gearing in Machine Design; July, 1954.

[ PP- 8361865 Primary Examiner-Robert E. Pul'frey Assistant ExaminerClifford D. Crowder [30] Foreign Application Priority Data Attorney,Agent, or FzrmJacob L. Kollm June 29, 1968 Germany 6751436 ABSTRACT 52us. c1 101/38 R, 101/124, 74/31, A Screen Printing machine formonochrome and P y- 74/600 chrome printing of cylindrical and conicalbodies. The 511 1111. cu. B411 17/22, B41f 17/28 machine comprises aPriming stonoil secured to a [58] Field of Search 101/38-40, 124,oiprooating Slido- A fixed doctor blade is also p 101 12 74 00 31 30 33337 35. vided. The stroke of the reciprocating slide is infinitelyadjustable. The bodies to be imprinted are rotated 56 References Ciabout their longitudinal axes in synchronism with the UNITED STATESPATENTS printing stencil. There is further provided an eccentric drivefor linearly displacing the printing stencil. 1,465,702 8/1923 Wile74/31 UX 2,702,001 2/1955 Gattuso 101/38 X 1 Claim, 7 Drawing FiguresPATENTEDFEBI 9:974

SHEET B [If 7 m. mm

INVEN'I'URI Wilfried Kummunn PAIENTE FEB 1' 9 1974 3" 7 92 I 6 5 7 SHEET5 0r 7 INVEN'I'OR:

Wilfrid Kummunn SCREEN PRINTING MACHINE FOR .CYLINDRICALOR CONICALBODIES The present invention concerns a screen printing machine having areciprocatable printing stencil with adjustable stroke and a fixeddoctor, for monochrome and polychrome printing of cylindrical or conicalbodies which rotate in synchronism with the displacement of the printingstencil about their longitudinal axis and are in rolling engagementalong the printing stencil.

It is an object of the invention to provide a screen printing machineavoiding former disadvantages, the machine being provided with a slidesupporting a printing stencil, the slide being displaceable in a simplemanner and adapted to be readily and accurately adjusted as regards itsstroke.

In accordance with the invention a screen printing machine of the typereferred to above is characterised by the feature that the slidecarrying the printing stencil .is linearly and continuously adjustablein the length of its stroke.

In a preferred embodiment the eccentric drive of a driving device forthe screen printing machine is provided with a driving disc continuouslyrotatable in a horizontal plane and has a radially adjustable bodynon-movably connected to the slide mounted thereon.

There is a push-rod arranged in a horizontal plane, which is mounted onthe adjusting body and is connected non-movably with a slit rotatablymounted on the slide relative to the printing stencil displacement.

An eccentric drive is provided, with a cross loop crank drive connectingthe slide carrying the printing stencil to the driving disc; this driveis provided with a guide on the slide carrying the printing stencil andextending at right angles to the movement direction of the slide, whichguide by means of a connecting member such as a gate block, pin, bush orthe like is connected with the driving disc.

In a further preferred embodiment the slide carrying the printingstencil is formed of two slides linearly displaceable with respect toone another, a gear wheel for the printing stencil displacement beingconnected to one of the two slides. The gear wheel engages in a rackedbar rigidly connected to the machine stand and meshes with a racked bardisplacing the printing stencil, whereby the stroke of the slidecarrying the printing stencil can be varied in a ratio of 2 1 relativeto the stroke of the eccentric drive.

To drive the driving disc, it is connected via an angle drive,preferably a bevel gear drive, to a driving shaft of the driving devicefor the screen printing machine, and the adjustment of the stroke of theprinting stencil is effected by means of an adjusting device connectedvia angle drives to the threaded spindle; the adjusting device may beprovided with a hand wheel for manual actuation which may be connectedto a stop device locating the threaded spindle and hence the adjustingbody in a position required.

A screen printing machine in accordance with the invention as describedabove is provided with printing stencil slide of simple structure,driven in a reliable manner and accurately and rapidly adjustable to thesize of stroke; this slide is linearly reciprocated by means of aneccentric drive (push-rod or push-crank) and continuously adjusted inthe region of the eccentric drive with regard to stroke length. Theconstruction for driving the screen slide is simple and economical toproduce. Furthermore the adjustment of the printing stencil stroke iseffected by an easy and accurate manipulation.

The adjustment of the size of stroke may be effected with the machine inoperation, thus making it unnecessary to shut down the screen printingmachine. The ad justing device also has an automatic lock, so thataccidental stroke variations during printing are impossible.

The invention will be described further with reference to theaccompanying drawings, in which:

FIG. 1 is a perspective view of a screen printing machine for monochromeand polychrome printing of cylindrical or conical bodies, provided witha slide with printing stencil displaceable linearly at right angles tothe axis of rotation of the body to be printed;

FIG. 2 is a cross-section through the same slide with printing stencil;

FIG. 3 is a longitudinal section through the same slide with a gearwheel connected with the slide and displaceable via a driving disc andpush-rod;

FIG. 4 is a plan view of the same slide with eccentric drive, partly insection;

FIG. 5 is a longitudinal section through a driving and adjusting devicefor moving the driving disc and for adjusting the slide stroke;

FIG. 6 is a plan view of the linearly displaceable slide of the screenprinting machine, partly in section, show ing an eccentric drive for theslide movement formed as a cross loop crank drive;

FIG. 7 is a longitudinal section through the same slide, provided with agear wheel which is connected to the driving disc via the crank drive.

A screen printing machine for monochrome and polychrome printing ofcylindrical and/or conical bodies 10, has a machine stand 1 l which isprovided with a feeding and removal device 14, such as a conveyor belt,fitted with a holding device 12 and adjusting devices feeding the bodies10 to be printed to a conveying device executing a circular movementpath. The said feeding device rotates in a horizontal plane at rightangles to the transporting device 13.. The latter 13 takes over thebodies 10 to be printed, conducts them aligned in the necessary startingposition, to theprinting position, and returns them after printing tothe feeding and removal device 14.

Above the transporting device 13 there is a slide 15 which is linearlydisplaceable parallel to the plane of the feeding and removal device15,. which slide is reciprocatingly displaced along parallel extendingguides 16, the degree of movement being adjustable.

A printing stencil 17 is rigidly mounted on this slide 15 and executes areciprocating movement with the slide 15 below a fixed ductor blade 18;it is moved by means of the transporting device in the region of theprinting position.

The displacement movement of the slide 15 and hence of the printingstencil 17 is effected by means of an eccentric drive 19 connected tothe driving device of the screen printing machine the stroke thereofbeing adjustable.

This eccentric drive 10 is provided with a driving disc 20 continuouslyrotating in a horizontal plane, in which there is a radially adjustableadjusting member 21 fixed to the driving disc 20 acting as eccentric.This adjusting member 21 is operationally connected with a push-rod 22in that the latter has a bearing lug 23 rotatably engaging a pin 21a ofthe adjusting member 21.

The other end of the push-rod 22 is rigidly connected to a pivot 24 of agear wheel 25 which in turn is in rolling engagement along a fixed rack26 and moves a displaceable rack 27.

The slide comprises two relatively displaceable slides, a main slide 28rotatably receiving the gear wheel and a printing stencil slide 29executing a displacement movement of twice the extent of slide 28. Bothslides 28,29 are mounted displaceable on guides 16. The gear wheel 25 isrotatably mounted in the main slide 28 by means of roller bearings 30and the pushrod 22, with a bearing head 32 provided with roller bearings31 engages the pivot 24 of the gear wheel 25, so that between gear wheel25 and push-rod 22 there is moving a rotating engagement. The fixed rack26 is secured by screws rigidly to a bracket 33 and on displacement ofthe main slide 28 the gear wheel 25 mounted therein is in rollingengagement over the fixed rack 26. The displaceable rack 27 which alsomeshes with the gear wheel 25 is secured to the printing stencil slide29 and on displacement of the main slide 28 with gear wheel 25 isdisplaced by the push-rod 22; on account of the rolling engagement ofthe gear wheel 25 of the displaceable rack 27 this movement is twice theextent of the displacement of the main slide 28. The eccentric mountingof the adjusting member 21 in the driving disc 20 imparts areciprocating displacing movement of the push-rod 22 being a rotarymovement of the driving disc 20, which produces a linear reciprocatingmovement of the printing stencil slide 29.

The rotary movement of the disc 20 is effected via an angle drive 34which is connected via a gear wheel 35 to the driving shaft, not shown,of the screen printing machine driving device. On the underside of thedriving disc 20 a hollow shaft 36 is mounted which at its free end isprovided with a bevel gear 37; this bevel gear 37 engages in a secondbevel gear 39 mounted on a shaft 38 rotatably mounted in the machinestand 11 at an angle thereto, which bevel gear is rigidly connected tothe gear wheel 35.

The rotary movement of the driving shaft of the driving device rotatesthe bevel gears 39,37, which via the hollow shaft 36 drive the drivingdisc 20 continuously in a horizontal plane, so that the two slides 28,29are displaced via the eccentric drive 19 and the body 10 to be printedis in rolling engagement along the reciprocating slide 29 with theprinting stencil 17.

The hollow shaft 36 extends vertically and is rotatably mounted in abearing 41 provided with roller bearings or the like; the shaft 38 is atright angles to the hollow shaft 36 in a horizontal plane, and its twoends are mounted in roller bearings 42,43 on the machine stand 11.

The adjusting member 21 is displaceably located in a radial groove 44extending from the pivot of the driving disc 20, and is traversed by athreaded spindle 45 extending along the groove 44, which spindle ispositively connected with the adjusting member 21.

The adjusting member 21 is displaced by rotating the screw spindle 45which is connected to an adjusting device 48 by means of an angle drive46, 47 such as a bevel gearing. A bevel gear 49 fixed to the screwspindle 45 meshes with a second bevel gear 51 fixed to a shaft passingthrough the hollow shaft 36. On the end of shaft 50 projecting from thehollow shaft 36 a further bevel gear 52 is provided which meshes with abevel gear 53; this bevel gear 53 is mounted on a hollow shaft 54 aboutshaft 38. The pairs 49, 51 and 52, 53 of bevel gears with shaft 50 andthe hollow shaft 54 each form an angle drive 46, 47 which are mutuallyoffset relative one another by On the free end of the hollow shaft 54there is a gear wheel 55 movably connected thereto which detachablyengages its teeth 56 in a stop device 57. This stop device 57, which hasa hearing 58 spaced from the shaft 38, receives a pin 59 of theadjusting device. This pin 59 has a hand wheel 60 on the end outside themachine stand 11, and is provided on the free end located Within themachine stand with a gear wheel 61. Between the bearing 58 and machinestand wall 62 there is a clearance provided including a compressionspring 63 which retains the adjusting device 48 under spring pressure,the gear wheel 61 in the normal position being out of engagement withthe gear wheel 55. The pin 59 provided on the hand wheel 60, and thegear wheel 61 may be displaced axially by a certain amount to givepositive connection between the two gear wheels 61, 55. To do so it isnecessary for the hand wheel 60 whilst overcoming the spring pressure,to be drawn axially outwards with the stop device 57, so that owing tothe change of position of the gear wheel 61 it meshes with the gearwheel 55 mounted to rotate about the shaft 38. ln this position the stopdevice 57 has been disengaged from the teeth 56 of the gear wheel 55 andby manually turning the hand wheel 50 the adjustment of the adjustingmember 21 for adjusting the stroke may be displaced on the driving disc20. When the hand wheel 60 is turned, then the meshing gear wheels 61,55 rotate the hollow shaft 54 via pin 59 which also rotates the bevelgears 53, 52 and the bevel gears 51, 49. The bevel gear 49 connected tothe screw spindle 45 now transmits its rotary movement thereto, so thatthe adjusting member 21 is displaced on the screw spindle 45 inaccordance with the direction of rotation. This displacement of theadjusting member 21 varies the distance thereof relative to the axis ofrotation of the driving disc 20 and adjusts the displacement movement ofthe push rod 22. The magnitude of the rod movement determines themagnitude of the reciprocating movement of the printing stencil 17.

When the hand wheel 60 is released, spring 63 forces the gear wheel 61out of engagement with the gear wheel 55 and the meshing device of bothgear wheels 55, 61 is interrupted; at the same time the stop device 57engages its teeth 56 in the teeth 56 of the gear wheel 55 and preventsthe hollow shaft 54 from rotating whereby the position of the adjustingmember 21 is fixed and prevented from accidental movement; theadjustment of the size of stroke may be carried out with onemanipulation by actuating the hand wheel.

The adjustment of the size of stroke of the printing stencil 17 isdetermined by the length of the screw spindle 45 and may be infinitelyvaried over a predetermined distance, so that the outer surface to beprinted may be adjusted to an optional printing surface. The eccentricdrive 19 provides a linear reciprocating movement of the printingstencil 17, and also an adjustment of the stroke of the printing stencil17 so that the various bodies to be printed may be accurately adjustedto the printing surface size in accordance with their outer surfaceformation.

A further embodiment of a drive for the slide i5 is shown in H68. 6 andI of the drawings. The machine is provided with a cross head drive 65connecting the slide carrying the printing stencil 17 with the drivingdisc 20, which drive causes the slide 15 to carry out a uniform linearreciprocating movement.

The basic structure of the slide 15 corresponds to the embodiment shownin FlGS. l to 4, except that the push rod 22 for the main slide 28displacement is omit ted.

This cross head drive 65 forming an eccentric drive for the main slide26 carrying the gear wheel 25, is provided with a guide extending atright angles to the direction of the slide movement, which guide isconnected to the driving disc 20 rotating in a horizontal plane by meansof a coupling member 67.

The guide 66 is provided at one end of the slide, it is arranged atright angles to the direction of movement of the slide and fixedthereto. The guide 66 extends to the underside of the main slide 28 andhas a displacing groove 66a. extending substantially over the wholewidth of the slide in which the coupling member 67 is in rolling and/orsliding engagement.

It is preferred to form the guide 66 as a rail of U- shapedcross-section secured to the underside of the slide and form thecoupling member 67 as a gate block, pin or bush. The coupling member 67has a rotatable connection with the pin 21a of the driving disc 21.

During rotary movement of the driving disc 20 driven by the drive of thescreen printing machine, the disc causes the slide 115 to carry out areciprocating linear movement via the cross head crank drive 65 and theslide 29 carrying the printing stencil 17 has imparted thereto adisplacement movement by the gear wheel 25 in rolling engagement overthe fixed rack 26 which is twice that of the main slide 26 moved by thecrank drive 65.

The coupling member 67 located in the guide 66 to form a connectionbetween main slide 28 and driving disc 20, executes a circular movementpath due to the rotation of the driving disc, and at the same time isreciprocated linearly in the guide 66, so that the slide 28, when thedriving disc is rotated, is reciprocated linearly and thus also impartsa linear displacement to the printing stencil slide 29 via the gearwheel 25 and the racks 26, 27, so that the stroke of the printingstencil slide 29 is in a ratio of2 l to the stroke of the cross headdrive 65.

The screen slide drive (eccentric drive 19 and cross head crank drive65) moves the printing stencil 117 over its whole displacement pathuniformly in both directions, since due to the drives 19, 65 favourableangle conditions between the gear wheel 25 and the driving disc 20 havebeen provided, the slight angular displacements occuring in the endregions (reversing points) of the slide movement, so that accurateprinting of the articles is ensured.

The printing stencil 17 has a uniform speed over the whole path of itsdisplacement and the articles to be printed are rotated synchronouslywith the displace ment of the printing stencil 17. The transmissiondrive from driving disc 20 to slide 15 and the arrangement of thedriving disc 20 in a horizontal plane is a cheap method of construction;furthermore these drive arrangements provide small drive components(driving disc 20, push rod 22) and relatively small distances betweendriving disc 20 and gear wheel 25.

it is within the scope of the invention to effect the transmission ofthe driving movement from the driving device to the driving disc bygears of alternative design; it is also possible to connect theadjusting device to the adjusting member by means of alternativegearings.

it is furthermore within the scope of the invention to arrange thetransporting device with holding devices for the articles to be printedso as to be adjustable about a pivot, so that the bodies with theiroptional outer surfaces may be adjusted to the printing stencil locatedin a horizontal plane.

The driving movement for the slide carrying the printing stencil, thetransporting device receiving the body to be printed and an adjustingdevice hold the body to be printed in a predetermined position in theprinting region and being in rolling engagement along the printingstencil are controlled so as to act in synchronism; all parts of thescreen printing machine may be driven by one driving device.

I claim:

1. A screen printing machine for monochrome and polychrome printing ofcylindrical and conical bodies, comprising a frame, a printing stencilmounted on said frame, a fixed doctor blade, means for reciprocatingsaid printing stencil which includes a slide means, said slide meansincluding a main slide and a printing stencil slide, means for effectingsynchronous rotation of said bodies about their longitudinal axes withthe reciprocation of the printing stencil, drive means for linearlydisplacing said slide means, said drive means comprising a driving disc,a stationary rack mounted on said frame, a gear wheel mounted in saidmain slide and meshing with said stationary rack, a movable rack mountedon said printing stencil slide and meshing with said gear wheel, saidmovable rack being parallel to said stationary rack and on the oppositeside of said gear wheel from said stationary rack, a U-shaped crossheadguide mounted on said main slide at one end thereof, a coupling membermounted on said driving disc and in rolling engagement with saidcrosshead guide for transferring rotary motion of said driving disc toreciprocating motion of said main slide, said printing stencil slidereciprocating in a 2:1 ratio relative to the stroke of said main slidedue to the rotation of said gear wheel be tween said stationary rack andsaid movable rack, an adjusting device for adjusting the position ofsaid coupling member radially of said driving disc to thereby vary thestroke of said main slide, said adjusting device comprising a screwspindle rotatably mounted in said driving disc and threadably engagingsaid coupling member whereby rotation of said screw spindle adjusts theposition of said coupling member, a bevel gear system for effectingrotation of said screw spindle, said bevel gear system connected betweensaid screw spindle and a first shaft parallel to said driving disc, saidfirst shaft having a gear mounted thereon which is selectivelyengageable with a second gear mounted on a second shaft parallel to saidfirst shaft, said second gear being normally out of engagement with saidfirst gear, said second shaft being spring biased in a direction such asto force said second gear out of engagement with said first gear andhaving a hand wheel thereon, whereby axial movement of said hand wheelmoves said second gear against the bias of said spring into engagementwith said first gear and rotation of said handwheel effects rotation ofsaid screw spindle through said bevel gear system to thereby adjust theposition of said coupling member and vary the stroke of said main slide.

=t l= =l= =l

1. A screen printing machine for monochrome and polychrome printing ofcylindrical and conical bodies, comprising a frame, a printing stencilmounted on said frame, a fixed doctor blade, means for reciprocatingsaid printing stencil which includes a slide means, said slide meansincluding a main slide and a printing stencil slide, means for effectingsynchronous rotation of said bodies about their longitudinal axes withthe reciprocation of the printing stencil, drive means for linearlydisplacing said slide means, said drive means comprising a driving disc,a stationary rack mounted on said frame, a gear wheel mounted in saidmain slide and meshing with said stationary rack, a movable rack mountedon said printing stencil slide and meshing with said gear wheel, saidmovable rack Being parallel to said stationary rack and on the oppositeside of said gear wheel from said stationary rack, a U-shaped crossheadguide mounted on said main slide at one end thereof, a coupling membermounted on said driving disc and in rolling engagement with saidcrosshead guide for transferring rotary motion of said driving disc toreciprocating motion of said main slide, said printing stencil slidereciprocating in a 2:1 ratio relative to the stroke of said main slidedue to the rotation of said gear wheel between said stationary rack andsaid movable rack, an adjusting device for adjusting the position ofsaid coupling member radially of said driving disc to thereby vary thestroke of said main slide, said adjusting device comprising a screwspindle rotatably mounted in said driving disc and threadably engagingsaid coupling member whereby rotation of said screw spindle adjusts theposition of said coupling member, a bevel gear system for effectingrotation of said screw spindle, said bevel gear system connected betweensaid screw spindle and a first shaft parallel to said driving disc, saidfirst shaft having a gear mounted thereon which is selectivelyengageable with a second gear mounted on a second shaft parallel to saidfirst shaft, said second gear being normally out of engagement with saidfirst gear, said second shaft being spring biased in a direction such asto force said second gear out of engagement with said first gear andhaving a hand wheel thereon, whereby axial movement of said hand wheelmoves said second gear against the bias of said spring into engagementwith said first gear and rotation of said handwheel effects rotation ofsaid screw spindle through said bevel gear system to thereby adjust theposition of said coupling member and vary the stroke of said main slide.